Structural Performance Evaluation of Triangular Rebar Through FEA-Based Topology Optimisation under Multi-Load Scenarios

Abstract

Traditional methods of reinforcing structures typically waste a large amount of material; however, there have been very few studies investigating the use of advanced materials and topology optimization for developing hollow triangular reinforcement bars that will perform under various load conditions. The focus of this study is to bridge this gap in research by performing finite element analysis (FEA) and topology optimization to determine the structural behaviour of three different types of triangulated reinforcement bars (i.e., Fe500, CFRP, GFRP and titanium) fabricated using advanced materials. For this study, numerical modelling was carried out using a tensile load of 10 kN, and four different types of reinforced concrete beam models were developed; all beams in this study were subjected to four separate points. To ensure they would all meet the displacement limit of 0.5 mm and be within good factors of safety (FS > 2.0), validation had to be completed against the applicable criteria. The results indicated that topology optimization allowed for approximately a 20–22% reduction in the amount of material used to reinforce the concrete beams. The maximum tensile stresses created by the solid bars were calculated as follows: Fe500 = 128.8 MPa, CFRP = 118.8 MPa, GFRP = 96.07 MPa and titanium = 135.9 MPa. Under combined loading, the maximum stresses produced by the optimized hollow triangulated bars also were calculated; they were as follows: Fe500 = 670.83 MPa, CFRP = 601.78 MPa, GFRP = 381.04 MPa and titanium = 531.08 MPa. In addition, the optimized design provided an annual cost savings of 20%, with estimated annual savings reaching ₹9,60,000 per 1000 m of titanium reinforcement.